Transcript RINA - Computer Science

On the Cost of Supporting
Multihoming and Mobility
Ibrahim Matta
Computer Science
Boston University
Joint work with Vatche Ishakian, Joseph Akinwumi, John Day
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Mobility = Dynamic Multihoming
 Hosts / ASes became increasingly multihomed
 Multihoming is a special case of mobility
 RINA (Recursive InterNetwork Architecture) is a
clean-slate design – http://csr.bu.edu/rina
 RINA routing is based on node addresses

Late binding of node address to point-of-attachment
 Compare to LISP (early binding) and Mobile-IP
 Average-case communication cost analysis
 Simulation over Internet-like topologies
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What’s wrong today?
Applications
Web, email, ftp, …
Applications
Transport
Transport
Network
Network
Network
Data Link
DL
DL
Data Link
Physical
PHY
PHY
Physical
128.10.0.0
128.197.0.0
 We exposed addresses to applications
 We named and addressed the wrong things
www.cs.bu.edu
128.197.15.10
RINA offers better scoping
Applications
Web, email, ftp, …
Transport
TCP, UDP, …
Network
IP
Data Link
Physical
IPC
Applications
Transport
IPC
Network
Network
DL
DL
PHY
PHY
IPC
Data Link
Physical
 E2E (end-to-end principle) is not relevant
 Each IPC layer provides service / QoS over its scope
 IPv6 is/was a waste of time!
 We don’t need too many addresses within an IPC layer
RINA: Good Addressing
want to send message to “Bob”
A
“Bob”B
B
IPC Layer
I1
To: B
Bob
I2
IPC Layer
 Destination application is identified by “name”
 App name mapped to node name (address)
 Node addresses are private within IPC layer
 Need a global namespace, but not address space
 Destination application process is assigned a port number
dynamically
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RINA: Good Addressing
want to send message to “Bob”
A
I1
BI2
B
IPC Layer
To: B
Bob
I2
IPC Layer
B, I1 , I2 are
IPC processes
on same
machine
 Late binding of node name to a PoA address
 PoA address is “name” at the lower IPC level
 Node subscribes to different IPC layers
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RINA: Good Routing
source
destination
 Back to naming-addressing basics [Saltzer ’82]
 Service name (location-independent) 
node name (location-dependent) 
PoA address (path-dependent)
 path
 We clearly distinguish the last 2 mappings
 Route: sequence of node names (addresses)
 Map next-hop’s node name to PoA at lower IPC level
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Mobility is Inherent
MH CH
 Mobile joins new IPC layers and leaves old ones
 Local movement results in local routing updates
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Mobility is Inherent
CH
 Mobile joins new IPC layers and leaves old ones
 Local movement results in local routing updates
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Mobility is Inherent
CH
 Mobile joins new IPC layers and leaves old ones
 Local movement results in local routing updates
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Compare to loc/id split (1)
 Basis of any solution to the multihoming issue
 Claim: the IP address semantics are overloaded as both
location and identifier
 LISP (Location ID Separation Protocol) ‘06
EIDx  EIDy
EIDx -> EIDy
RLOC1x  RLOC2y
EIDx  EIDy
Mapping: EIDy  RLOC2y
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Compare to loc/id split (2)
 Ingress Border Router maps ID to loc, which is the
location of destination BR
 Problem: loc is path-dependent, does not name the
ultimate destination
EIDx -> EIDy
RLOC1x RLOC2y
EIDx  EIDy
Mapping: EIDy  RLOC2y
LISP vs. RINA vs. …
 Total Cost per loc / interface change =
Cost of Loc / Routing Update +
r [Pcons*DeliveryCost + (1-Pcons)*InconsistencyCost]
r: expected packets per loc change
Pcons: probability of no loc change since last pkt delivery
 RINA’s routing modeled over a binary tree of IPC
layers: update at top level involves route propagation
over the whole network diameter D; update at leaf
involves route propagation over D/2h, h is tree height
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LISP
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LISP
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RINA
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RINA
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RINA
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MobileIP
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LISP vs. RINA vs. …
8x8 Grid Topology
RINA uses 5 IPC levels; on average, 3 levels get affected per move
LISP
RINA
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Simulation: Packet Delivery Ratio
 BRITE
generated 2level topology
 Average path
length 14 hops
 Random walk
mobility model
 Download
BRITE from
RINA
LISP
www.cs.bu.edu/brite
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Simulation: Packet Delay
LISP
RINA
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Bottom Line: RINA is less costly
 RINA inherently limits the scope of
location update & inconsistency
 RINA uses “direct” routing to
destination node
 More work: prototyping
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RINA papers @
http://csr.bu.edu/rina
Thank You
Questions?
I. Matta